# PEPPOL-EN16931-R020

Source: https://xmlvalid.com/rules/PEPPOL-EN16931-R020

> Seller electronic address MUST be provided

- Level: error
- Rule sets: Peppol BIS Billing 3.0 rules 3.0.21, XRechnung 3.0 rules (UBL) 2.6.0
- Context: `cac:AccountingSupplierParty/cac:Party`
- Test: `cbc:EndpointID`

> Seller electronic address MUST be provided

- Level: error
- Rule sets: XRechnung 3.0 rules (CII) 2.6.0
- Context: `ram:SellerTradeParty`
- Test: `ram:URIUniversalCommunication/ram:URIID`

## Why it fails

- The seller party has no `cbc:EndpointID`, its Peppol address.

## How to fix it

- Add `cbc:EndpointID` with its `schemeID` to `cac:AccountingSupplierParty/cac:Party`.

Validate a document against these rules: https://xmlvalid.com/validate